Conventionally, applicators for delivering substances to body cavities, such as the vagina and rectum, comprise a blunt, hollow tube or barrel into which a plunger can be inserted. Typically, these tubes are formed of rigid plastic material that has no flexibility during insertion, which often makes use and application difficult and painful for the user.
In many cases, the leading end of the tube includes internal threads to attach the tube to a dispenser for loading the applicator with cream or other flowable substances. When the substance is discharged into the cavity, the threads typically are filled by the substance, resulting in inaccurate dosing. Additionally, this may create hygiene problems for the user because cleaning the tube may not remove all of the substance from the threads and thus bacteria may hide in the threads.
Typically, the user loads the applicator based on markings that appear on the body of the plunger that is positioned inside the tube. If the user does not ensure that the volume of the tube below the plunger is completely filled by the substance (i.e., there are no air gaps inside the tube), then further dosing inaccuracies may occur. Dosing inaccuracies may also occur when loading because the applicator requires the user to squeeze the substance out of the dispenser and into the applicator. In many cases, when the user squeezes the dispenser, the dispenser sucks back some or all of the substance, making it difficult for the user to load the applicator. Thus, loading the applicator requires skill and tedious attention to detail by the user, thereby making it difficult for the user to obtain accurate dosing. Specifically, the user must carefully squeeze the dispenser until the substance reaches the desired marking and then carefully un-thread the applicator from the dispenser to release the vacuum to obtain accurate dosing.
Usually, the user dispenses the substance from the applicator into the body cavity by depressing the plunger into the tube. However, a certain amount of clearance between the plunger and the tube is necessary to avoid leakage of the substance back into the tube. On one hand, if there is too much space between the plunger and the tube, leakage may occur because the substance may remain in the space between the tube and the plunger. On the other hand, if there is not enough space between the plunger and the tube, the plunger may get stuck or bend in the tube, and leakage may result from the substance blowing by the plunger and back into the tube. Consequently, if the clearance is too much or too little, leakage occur, resulting in inaccurate dosing.
Thus, it may desirable to provide an applicator with a more flexible/smoother leading end for more comfortable use, a connection design that eliminates the inaccuracies associated with the internal threads in the applicator, as well as a way to improve the dosing accuracy of flowable material into the applicator.